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Decouple the values of TOAST_TUPLE_THRESHOLD and TOAST_MAX_CHUNK_SIZE.

Add the latter to the values checked in pg_control, since it can't be changed
without invalidating toast table content.  This commit in itself shouldn't
change any behavior, but it lays some necessary groundwork for experimentation
with these toast-control numbers.

Note: while TOAST_TUPLE_THRESHOLD can now be changed without initdb, some
thought still needs to be given to needs_toast_table() in toasting.c before
unleashing random changes.
This commit is contained in:
Tom Lane
2007-04-03 04:14:26 +00:00
parent 4fea0ca8f3
commit b3005276eb
8 changed files with 113 additions and 47 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.230 2007/03/29 00:15:37 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.231 2007/04/03 04:14:26 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -1420,7 +1420,13 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
* Note: below this point, heaptup is the data we actually intend to store
* into the relation; tup is the caller's original untoasted data.
*/
if (HeapTupleHasExternal(tup) || tup->t_len > TOAST_TUPLE_THRESHOLD)
if (relation->rd_rel->relkind == RELKIND_TOASTVALUE)
{
/* toast table entries should never be recursively toasted */
Assert(!HeapTupleHasExternal(tup));
heaptup = tup;
}
else if (HeapTupleHasExternal(tup) || tup->t_len > TOAST_TUPLE_THRESHOLD)
heaptup = toast_insert_or_update(relation, tup, NULL,
use_wal, use_fsm);
else
@ -1777,7 +1783,12 @@ l1:
* because we need to look at the contents of the tuple, but it's OK to
* release the content lock on the buffer first.
*/
if (HeapTupleHasExternal(&tp))
if (relation->rd_rel->relkind == RELKIND_TOASTVALUE)
{
/* toast table entries should never be recursively toasted */
Assert(!HeapTupleHasExternal(&tp));
}
else if (HeapTupleHasExternal(&tp))
toast_delete(relation, &tp);
/*
@ -2075,9 +2086,17 @@ l2:
* We need to invoke the toaster if there are already any out-of-line
* toasted values present, or if the new tuple is over-threshold.
*/
need_toast = (HeapTupleHasExternal(&oldtup) ||
HeapTupleHasExternal(newtup) ||
newtup->t_len > TOAST_TUPLE_THRESHOLD);
if (relation->rd_rel->relkind == RELKIND_TOASTVALUE)
{
/* toast table entries should never be recursively toasted */
Assert(!HeapTupleHasExternal(&oldtup));
Assert(!HeapTupleHasExternal(newtup));
need_toast = false;
}
else
need_toast = (HeapTupleHasExternal(&oldtup) ||
HeapTupleHasExternal(newtup) ||
newtup->t_len > TOAST_TUPLE_THRESHOLD);
pagefree = PageGetFreeSpace((Page) dp);

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.72 2007/03/29 00:15:37 tgl Exp $
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.73 2007/04/03 04:14:26 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -291,6 +291,12 @@ toast_delete(Relation rel, HeapTuple oldtup)
Datum toast_values[MaxHeapAttributeNumber];
bool toast_isnull[MaxHeapAttributeNumber];
/*
* We should only ever be called for tuples of plain relations ---
* recursing on a toast rel is bad news.
*/
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
/*
* Get the tuple descriptor and break down the tuple into fields.
*
@ -360,6 +366,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
bool has_nulls = false;
Size maxDataLen;
Size hoff;
char toast_action[MaxHeapAttributeNumber];
bool toast_isnull[MaxHeapAttributeNumber];
@ -370,6 +377,12 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
bool toast_free[MaxHeapAttributeNumber];
bool toast_delold[MaxHeapAttributeNumber];
/*
* We should only ever be called for tuples of plain relations ---
* recursing on a toast rel is bad news.
*/
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
/*
* Get the tuple descriptor and break down the tuple(s) into fields.
*/
@ -512,15 +525,15 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
*/
/* compute header overhead --- this should match heap_form_tuple() */
maxDataLen = offsetof(HeapTupleHeaderData, t_bits);
hoff = offsetof(HeapTupleHeaderData, t_bits);
if (has_nulls)
maxDataLen += BITMAPLEN(numAttrs);
hoff += BITMAPLEN(numAttrs);
if (newtup->t_data->t_infomask & HEAP_HASOID)
maxDataLen += sizeof(Oid);
maxDataLen = MAXALIGN(maxDataLen);
Assert(maxDataLen == newtup->t_data->t_hoff);
hoff += sizeof(Oid);
hoff = MAXALIGN(hoff);
Assert(hoff == newtup->t_data->t_hoff);
/* now convert to a limit on the tuple data size */
maxDataLen = TOAST_TUPLE_TARGET - maxDataLen;
maxDataLen = TOAST_TUPLE_TARGET - hoff;
/*
* Look for attributes with attstorage 'x' to compress
@ -583,7 +596,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
/*
* Second we look for attributes of attstorage 'x' or 'e' that are still
* inline.
* inline. But skip this if there's no toast table to push them to.
*/
while (heap_compute_data_size(tupleDesc,
toast_values, toast_isnull) > maxDataLen &&
@ -695,7 +708,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
}
/*
* Finally we store attributes of type 'm' external
* Finally we store attributes of type 'm' external, if possible.
*/
while (heap_compute_data_size(tupleDesc,
toast_values, toast_isnull) > maxDataLen &&